Optional parameters: Difference between revisions
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(("zap" "zip" "Zot") ("a" "b" "c") ("" "q" "z"))</lang>
=={{header|OCaml}}==
OCaml has optional named parameters.
<lang ocaml>let sort_table ?(ordering = compare) ?(column = 0) ?(reverse = false) table =
let cmp x y = ordering (List.nth x column) (List.nth y column) * (if reverse then -1 else 1) in
List.sort cmp table</lang>
Example uses:
<lang ocaml># let data = [["a"; "b"; "c"]; [""; "q"; "z"]; ["zap"; "zip"; "Zot"]];;
val data : string list list =
[["a"; "b"; "c"]; [""; "q"; "z"]; ["zap"; "zip"; "Zot"]]
# sort_table data;;
- : string list list =
[[""; "q"; "z"]; ["a"; "b"; "c"]; ["zap"; "zip"; "Zot"]]
# sort_table ~column:2 data;;
- : string list list =
[["zap"; "zip"; "Zot"]; ["a"; "b"; "c"]; [""; "q"; "z"]]
# sort_table ~column:1 data;;
- : string list list =
[["a"; "b"; "c"]; [""; "q"; "z"]; ["zap"; "zip"; "Zot"]]
# sort_table ~column:1 ~reverse:true data;;
- : string list list =
[["zap"; "zip"; "Zot"]; [""; "q"; "z"]; ["a"; "b"; "c"]]
# sort_table ~ordering:(fun a b -> compare (String.length b) (String.length a)) data;;
- : string list list =
[["zap"; "zip"; "Zot"]; ["a"; "b"; "c"]; [""; "q"; "z"]]</lang>
=={{header|Tcl}}==
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